Don't go making wild assumptions like that without citing your sources

That's fair, it's just that the context suggested otherwise.

I guess if he's from northern England, and by "dinner" means the midday meal, then it makes sense. Otherwise there is no universe where baked potatoes are served for a fancy dinner. Roast potatoes are a part of a fancy dinner, though. The two cooking techniques are similar enough that I think it's not unreasonable to assume, again given the context, that it's just the wrong word.